Pharmacokinetics and Bioequivalence of 2 Immediate-Release Tofacitinib Tablet Formulations in Chinese Healthy Volunteers Under Fasting and Fed Conditions

The purpose of this study was to evaluate the bioequivalence of a generic immediate-release tofacitinib tablet versus a brand-named immediate-release tofacitinib tablet under fasting and fed conditions, and the food effect on pharmacokinetic profiles of the both formulations. This randomized, open-label, 2-period, crossover, bioequivalence study included 52 healthy Chinese subjects (fasting cohort: n = 26; fed cohort: n = 26). The subjects were assigned to receive a single 5-mg dose of generic or brand-named tofacitinib. Blood samples were collected at predosing and up to 14 hours after dosing. Tofacitinib concentrations in plasma were analyzed by high-performance liquid chromatography-tandem mass spectrometry. Safety was monitored. There were no significant differences in maximum plasma concentration, area under the plasma concentration-time curve from time zero to time t (AUC(0-t)), AUC from time zero to infinity (AUC(0-infinity))(,)and terminal elimination half-life between the test and reference formulations (allP> .05); high-fat food had no significant effect on AUC(0-t), AUC(0-infinity,)or terminal elimination half-life of immediate-release tofacitinib tablets (allP> .05). The 90% confidence intervals of the test/reference ratios of log-transformed maximum plasma concentration, AUC(0-t), and AUC(0-infinity)were within the range of 80% to 125% under both fasting and fed conditions. No serious adverse events were reported. The 2 formulations of immediate-release tofacitinib tablets are bioequivalent and well tolerated under both fasting and fed conditions in healthy Chinese volunteers. Food had no clinically relevant effects on drug exposure of tofacitinib.